Directors of some of Britain's biggest companies face steep fines for not listing their offshore subsidiaries, as campaigners step up pressure over corporate tax avoidance.

Charity ActionAid made a complaint to Companies House last week against 49 companies in the FTSE 100, saying they did not comply with requirements to list all subsidiaries.

Failure to adhere to this requirement can result in a fine of up to £1,000 for each director and then a fine of up to £100 a day for continued contravention of this rule, said a spokesman for Companies House.

ActionAid, which is dedicated to ending poverty, discovered that many companies had failed to disclose a full list of their subsidiaries during its campaign to find out how many subsidiaries of British companies were in tax havens.

After the complaint, made on Thursday, 13 companies, including supermarket giant Morrisons and insurer Standard Life, told Financial Mail they intended to resubmit details of their global subsidiaries.

I'm delighted Action Aid have done this.

I'm delighted it's been picked up by the Mail.

This complaint has been overdue since Action Aid worked with the Tax Justice Network and others in 2009 to produce a report called 'Where on Earth Are You?' When doing so we found just 33 of the FTSE 100 companies complied with what seemed like their legal requirement to file a full group structure at that time. It looks like Action Aid have now found the ratio has gone up - but it's still a long way short of being acceptable. I hope some real action from Companies House follows.